Dense depth image synthesis via energy minimization for three-dimensional video

•This paper synthesis dense depth images via a block-based energy minimization model.•A multi-label graph structure for graph cut model is constructed.•Depth video coding gains can be found via dense depth image synthesis.

Dense depth image is crucial for all three-dimensional (3D) video systems because it is utilized to record the space coordinates of all visible pixels for its corresponding color image. In asymmetric framework of 3D video system, depth image located at non-key-time is usually discarded for the sake of bandwidth saving. In order to construct a complete dynamic 3D scene, the method of dense depth image synthesis is needed. In this paper, we propose a synthesis method through energy minimization for the asymmetric framework of 3D video. Block-based label and metric function is processed in the proposed energy function, and a multi-label graph structure is also proposed to minimize the energy function. In the experiments, the proposed method is utilized in the asymmetric framework for verification. The experimental results show that our method can have better objective and subjective performance on all selected test sequences.